Paper cans



D. H. HESTER Oct. 16, 1962 PAPER CANS 5 Sheets-Shea?I 1 Filed NOV. lO, 1958 INVENTOR. www/f #55 me BY Mn,

A (Tam/EK? D. H. HESTER Oct. 16, 1962 PAPER CANS Filed Nov. 10, 1958 5 Sheets-Sheet 2 D. H. HESTER oct. 16, 1962 PAPER CANS 3 Sheets-Sheet 3 Filed Nov. l0, 1958 INVENTOR. n////r A( #ESTE/a A Trae/115W' United States Patent Office Patented Oct. 16, 1962 Filed Nov. 10, 1958, Ser. No. 773,031 16 Claims. (Cl. 229-14) My invention relates to disposable paper cans characterized in general by a body formed of paper or other fibrous material, to the method of making such cans and to improved tube winding machine accessories with which the cans of my invention may be conveniently made.

Characteristically, liquid containers of the type intended for any appreciable shelf life or, alternatively, intended for the storage of chemically active compositions are commonly made of metal, glass, molded plastic, etc.

Plastic containers are expensive, glass bottles are heavy and breakable, and metal cans corrode. Although metal cans are generally coated on the inside, the coating is more often than not fractured in the course of fabrication.

A principal object of my invention, therefore, is to provide a can adapted for the storage of liquids over protracted periods which has essentially a paper body which may be inexpensively formed on ordinary spiral tube winding machinery.

Another object of my invention lies in the provision of an essentially paper body for a liquid container having, however, a heat-sealed, impermeable plastic lining.

Another object of my invention is the provision of a can having an essentially paper body which is not only adapted for the storage of liquids but also to withstand immersion or other exposure to moisture or corrosion from without.

Still another object of my invention lies in a container formed of a body of the above-described character wherein novel provision is made for sealing the ends of such a body so as to provide a complete container.

A still further object lies in the provision of novel ends for can bodies of the character described which are easily but effectively applied, which are not subject to corrosion and which are rigid and strong to maintain the form of the container body.

My invention is further directed to the method of making such a can and, therefore, a further object of my invention may be regarded as a method whereby a container body as described above may be formed on conventional paper tube making machinery and whereby the ends of the body portions of each can may be sealed so as to constitute a container meeting the purpose of being capable of storing chemically active liquids or storing liquids of any description over protracted periods of time.

While I illustrate in the following detailed description a method whereby a can of my invention may be made on conventional tube winding machinery, the practice of my invention requires in some instances, a controlled heat differential in certain areas of the winding process. Accordingly, a still further aspect of my invention may be regarded as a modification of such machinery, whereby different zones in the winding process may be held at different temperatures to achieve desirable structural characteristics.

Other objects and advantages of my invention will be apparent from the following description and drawings, of which:

FIG. 1 is a central longitudinal section through a can illustrative of my invention;

FIG. 2 is a sectional view of the lower left corner of FIG. l, showing the parts thereof as assembled but not yet sealed together;

`LFIG. 3 is a section through a wall of a container similar to that of FIG. l, showing, however, a different wall structure;

FIG. 4 is a central section through the upper end of a container similar to that of FIG. 1, showing, however, a modified end structure;

FIG. 5 is a fragmentary section through a top end mem-ber showing alternative means whereby the two parts of the member may be interconnected before final attachment; f

FIG. 6 is a section similar to FIG. 5, showing, however, the structure after final attachment;

FIG. 7 is a central section through the upper portion of a container similar to that of FIG. 1, showing, however, another form of top end;

FIG. S is a diagrammatic top plan view of the mandrel of a spiral tube winding machine illustrating the assembly of container body stock thereon;

FIG. 9 is a side elevation of a pre-heating feed for certain layers of the container body stock as illustrated in FIG. 8 and may be regarded as taken substantially from the line 9 9 of FIG. 8, looking in the direction of the arrows;

FIG. l0 is a central vertical section through a novel and improved mandrel for a spiral tube winding machine providing heated and cooled Zones over the length of the mandrel;

FIG. ltl is an enlarged fragmentary section through a wall of the body of my container, showing the laminated structure thereof taken substantially along the line 11-11 of FIG. l, looking in the direction of the arrows;

FIG. l2 is a fragmentary section through a modified form of container end showing an alternative channel structure for securing the end to the container body, shown before sealing; and,

FIG. 13 is a view similar to FIG. l2 shown, however, after sealing.

In FIG. 1 is illustrated one embodiment of my invention as exemplified in a liquid container. The cylindrical body portion iti thereof consists of a tube formed of spirally wound paper l2 or other fiber or the like, and an inner, liquid-impermeable, spirally wound, plastic liner 14. The spiral winding of both liner and tube are made on conventional spiral tube winders in a fashion to be later described. i

The plastic liner 14 is desirably of two-ply construction. Although many materials will serve as a feasible liner material, such as polyethylene and the like, I have found that a film formed of Mylar (a condensation product of polyethylene terephthalate with ethylene glycol) is well suited for this purpose and is sufficiently inexpensive and easily handled so as to make large scale production of this kind of container feasible. I prefer using a Mylar film having a polyethylene or other polymeric coating on one surface thereof, the polymer desirably being one having generally the same inertness as polyethylene and a fusing temperature below that of the base film. The liner is formed by laying two plies of the coated Mylar on one another, the coated sides facing each other,

, and fusing the coatings together so as to obtain the abovedescribed two-ply construction. The paper or ber is wound on the exterior of the Mylar cylinder and secured thereto by appropriate adhesives.

In completing a can, an appropriate length of the abovedescribed lined tubing is taken and can ends, top 16 and bottom 18 are secured to the ends of the tube.

In the illustrated embodiment, the bottom is formed of a thin sheet metal shell 20 and a stable, liquid-impervious plastic shell 22. The metal shell, as illustrated, includes a central disk portion 24 and a relatively deep, depending, upwardly open, channel-shaped rim 26 surrounding it. The plastic shell 22 overlies the disk portion 24 and follows generally the interior contours of the channel 26 as at 2S on the periphery thereof so as to leave an annular channel 3th of less width than the channel 26 formed in the metal shell. 'Ihe plastic shell, however, stops short of the upper edge 31 of the outside 29 of the metal channel as particularly illustrated in FIG. 2.

To secure the container bottom to the body, one end of the body is inserted into the channel 30 against the bottom thereof. Thereafter, continuous, peripheral, opposite beads or indentations 32 are impressed by some such means as rolling, wiping or crimping around both the inside and the outside surface of the metal rim 26 with suicient force to deform and compress the plastic shell and, inwardly of the plastic shell, the body part contained within channel 30 as at 33. The metal, of course, is permanently deformed by the rolling or crimping and maintains the compressive deformation of the plastic channel and the end of the body. Simultaneously, the upper edge 31 of the outside of the metal channel is crimped inwardly against and into the side of the container body as best seen in FIG. 1 to constitute an inturned flange biting into the side of the body. The compression and deformation of the container body by the liange 3l and the beads 32 serve effectively to anchor the bottom 18 of the container to the body and to secure the liner 14 against the plastic shell in positive liquidtight relation.

Where non-corrosive products are to be packaged, the plastic shell may be omitted and the channel 26 of the metal shell be formed to contain closely the end 33 of the body. Upon forming the beads, the metal seizes directly on the body end.

The container top 16 has essentially the same rim structure as the bottom 18 for securing the top to the body 10. As illustrated in FIG. l, the top again consists of metal shell 34 and an interiorly conforming, inside plastic shell 35. The metal top again includes an upstanding, downwardly directed annular channel 36 and the plastic shell 35 follows around the channel 36 to deline channel 37 of reduced size which, again, receives snugly the open end of the tubular body l0. The top 16 is secured to the upper end of the container body in the same fashion as the bottom and includes the inwardly extending flange 38 and the opposite beads 4l) rolled into the inside and outside surfaces of the channel 36.

The pictured container top differs from the container bottom in providing a central pouring spout 4l. The metal shell 34 of the container top slopes conically inward and upward from the channel 36 and terminates in an outwardly recurved bead 42 leaving a circular central opening 44 in the center thereof. The plastic shell conforms to the underside of the metal shell in its inward and upward slope but terminates in a substantially cylindrical projection 46 extending upwardly beyond the bead 42.

The cylindrical projection 46 is undercut on its exterior surface downwardly from the upper end thereof as at 48 to snap over the inside of the rolled bead 42 of the metallic shell and maintain the cylindrical projection 46 of the plastic shell in its position extending outwardly from the central aperture 44 in the metal shell.

The inside surfaces 49 of the cylindrical projection are upwardly slightly divergent.

A plastic closure cap 50 is likewise illustrated. This cap should be made of deformable plastic such as polyethylene or the like. The cap has a central, thick stopper portion 52 having upwardly divergent sides 54, to match the divergence of the inside of the pouring spout 41 dened by the cylindrical projection 46 of the plastic shell and effect a tight closure thereagainst. Outwardly of the stopper portion, the thickness of the cap is reduced as at 56 to receive the pouring spout edge 46 and the upper portion of the metal bead 42 and the cap terminates on its edges in a downwardly extending resilient skirt 58 snapping tightly over or removable from the lateral edges of the bead 42. The metal bead 42, it will be noted, serves the dual function of supporting the pouring spout defined by the cylindrical projection 46 of the plastic shell by virtue of the undercut 4S in the plastic shell and likewise provides the surface over which the skirt 58 of the cap snaps to latch the cap in place on the container.

FIG. 4 illustrates an alternative form of container top which, again, consists of a metal shell 60 and a plastic shell 62, each having the same rim structure as in the top closure described above. In this instance, however, the metal shell extends cylindrically upward as at 64 in its central portion to detine an elongated pouring spout. The plastic shell 62 again follows the inside conformation of the metal shell and therefore has an inner, tubular, upward extension 66 extending up inside the cylindrical metal spout and lying directly against the inside wall thereof. The upward extension 64 ofthe metal shell may be spirally embossed in order to provide threading 68 on the exterior thereof. The upward extension 66 of the plastic shell desirably has a comparable spiral thread 70 running about the exterior thereof in order to fit into the back side of the threading of the metal extension. In this fashion, an interengagement between the spiral bead of the pouring spout of the plastic shell and the back or inner side of the threading in the metal pouring spout serves to anchor the plastic spout in position within the metal pouring spout. The plastic and metal shells may be further secured together adjacent the pouring spout by a bead 72 formed in the plastic pour spout to interlock with the annular indentation 73 in the metal shell below the threading 68. This type of top container closure will receive then an interiorly threaded plastic screw cap 74.

It may be desirable to latch the plastic shell more iirrnly to the meal shell than simply by the interengagement of the threading 68 and 70 or the bead 72 in the top ot' FIG. 4 or by the undercut 48 in the top of FIG. l. To this end, I may provide a ring 0f punched holes 76 in the metal shell 6D near but outside the area of the pouring spout. The holes 76 are round and should have upwardly recurving walls 7 3. To cooperate with these punched holes, I provide a plurality of correspondingly situated and spaced plastic buttons titi formed integrally with the plastic shell and standing upward therefrom. The plastic buttons have a relatively narrow neck 82 and then flare outwardly to a head 84 so that the curvature of the neck as it extends to the head 84 of the buttons is the complement of the curvature of the recurved walls 78 of the holes 76. By forcing the buttons through the holes 76 in the metal shell, the plastic shell is firmly secured to the metal shell in an area immediately next to the pouring spout so as to prevent positively any dislocation of the plastic shell within the metal shell in the critical area of the pouring spout.

This buttoned together structure may also be achieved by forming the buttons as cylindrical studs and heating the studs over with heat and pressure into the illustrated form after assembly of the two parts.

FIGS. 5 `and 6 illustrate a second method of obtaining the direct and positive attachment between the plastic and metal shells of the top closure. In these figures, a portion of the plastic shell 86 and metal shell 88 are shown. The plastic shell has a plurality of tubular studs 9i) formed therein and arranged annularly about the area of the pouring spout. The studs are long enough to stand up through and above correspondingly located holes 92 formed in the metal shell 88. The holes 92 should have a smaller diameter than the exterior of the studs 90 but should ybe stretched by embossing them conically outward as may behest `seen in FIG. 5 to receive the studs 90. To assemble the plastic shell to the metal shell, the two cornponents are put together with appropriate surfaces against each other and the studs 9) extending up through the holes 92 in the metal shell. Thereafter, the upwardly embossed edges of the hole 92 are pressed downward to restore them again to the general plane of the top closure and by so doing reduce their diameter to compress inwardly and bear against the outer side walls of `the studs 90 as best seen in FIG. 6.

FIG. 7 is illustrative of still another form of top container end. In this instance, the use of the metal shell is avoided, but certain metal components are still employed. This form or" end employs a plastic shell 94 consisting of a broadly conical surface 96 with a central cylindrical pouring spout 98 and a peripheral, upwardly extending flange 1110. In this form of my invention, an annular metal edge seal 102 is employed which is U- shaped in cross section. The peripheral flange 1111) of the container top is proportioned to lit vsnugly inside the upper end of the body 1114 of the container. The container top is mounted within the container body 11M with the upper edge 106 of the flange aligned with the upper edge of the container body 1611. The annular metal edge seal 1152 is then dropped over the flange 161i and upper end of the container body to enclose them and opposite annular grooves 168 are then rolled in the inside and outside `surfaces of the edge seal to deform and pinch Itogether the contained flange 101i and upper end of the body member 164 yso as to secure a liquid-tight seal therebetween.

This form of container top end is likewise intended for use with a screw cap. While threading may be preformed in plastic materials to hold a screw cap, in the relatively thin gauge of plastic illustrated, the spout may not be rigid enough to keep a screw cap lirrnly in place. I, therefore, provide superior cap retention in this modification by .furnishing a tubular metal sleeve 110 having a spiral thread 112 rolled into the surface thereof. Comparable threading 114 will be formed on the exterior of the plastic pouring spout 98. The metal sleeve 110` is inserted over and around the plastic pouring spout so that the threads of the plastic spout portion engage the threading in the reverse or inside surface of the metal sleeve 111). I then roll under the bottom edge 116 of the tubular sleeve so as to cause the edge of the sleeve to dig into the plastic of the pouring spout and secure the metal sleeve positively to the plastic vspout portion. With the positive engagement between the rolled-under edge 116 of the `sleeve 1119, the engagement between the threading on the plastic Vspout portion and the reverse side of the sleeve threading provides additional support and engagement |between the plastic spout portion and the sleeve. In this fashion, I obtain rigid threads on an otherwise all-plastic container closure which the threading of a screw cap may engage securely.

Although the containers described have diterent top and bottom ends, it will be understood that both ends may be like that illustrated as the bottom end'18 of FIG. 1 to provide a can essentially conventional in appearance as, for instance, a -tin can of peas or tomatoes.

FIGS. l2 and 13 illustrate an alternative rim structure adapted for sealing by conventional can seaming machinery. Illustrated here is la metal shell 101 only as for packaging non-corrosive products. `In this modification, the channel 103 is made wider than in the form described before, and the bead or `depression 105 in the inside wall is formed before assembly of the shell 101 to the container body end 167. The width of the channel is such as to provide room between the bead 105 and the outer wall 109 of the channel for reception of the end of the container body.

In sealing, the container body end 167 is inserted into the channel 1113 as illustrated in FIG. l2. Thereafter, the seaming machine bends the outer wall 109 inward and rolls an indentation 111 `therein as illustrated in FIG. 13. The inward bending of wall 169 and the bead 111 formed ltherein forces the container body end against the preformed inner bead 1115 to compress the body end between the beads as in the first described form. The liquid-tight character of a container formed in this fashion is positively assured by the compressive 'bearing of the inner bead against the plastic liner 113.

To make the tubing of which the body of my container is formed, certain modifications in conventional spiral tube winding must be made. My invention contemplates the application of heat to the plastic material of which the liner is formed. This heat may be provided before the materials are delivered to the winding mechanism or it j may be provided afterwards.

In FIGS. 8 and 9, I illustrate mechanism whereby the required heat is delivered to the plies which go to make up my container lining before the winding process. A conventional spiral tube winding machine is desirably employed in the manufacture of my container tubing of which the mandrel 12d only is illustrated. The machine includes cross belts 122 driven by appropriate pulleys 124 which apply pressure to the tubing and cause the tubing formed on the mandrel to migrate spirally along the mandrel. The direction of movement of the tubing is from left to right on the mandrel, the mandrel being mounted at the left-hand end marked 126. The several plies of the tubing are delivered to the mandrel consecutively from Mylar supply rolls 128 and 129, paper rolls 130 and 131 and, for one form of my container, Mylar rolls 132 and 133.

FIG. 9 shows the mechanism by which heat is applied to the first Mylar strip prior to its deposit on the mandrel 1241. The supply roll 128 delivers continuously the strip of Mylar, coated on the outside, to an idler roller 134 which, in turn, delivers the strip to a heated roller 136 having interior heat generating and controlling mechanism such as a thermostatically controlled electric heating coil. As heated rollers are so well known, illustration of the lactual heating mechanism is believed unnecessary. The roller 136 is a simple cylindrical roller having edge flanges 138 to assure proper direction of the strip passing over it. From the roller 136, the strip continues over a heating iron 14@ and thence to the mandrel 126.

The iron is an electrically heated, thermostatically controlled member having a smooth convex upper surface 142 which effects -a smooth transition of the Mylar strip from the heating roller 136 to the surface of the mandrel 1211 without any major departure from a heated surface. The iron is situated, as will be appreciated from the drawings, between the heating roller 136 and the mandrel 120 and has lower surfaces 144, 146 conforming closely to the surfaces of the roller 136 and the mandrel 120 in concentric relation thereto in order to provide an upper convex surface which extends very closely in bridging relation to the surfaces of the heating roller and of the mandrel. The heating roller 136 and the iron 140 are controlled and adjusted to cause a continuous heating of the Mylar in the course of its passage thereover to cause the coating thereof to become tacky or adhesive and to maintain such condition of tackiness to a point on the travel of the strip along the mandrel beyond that at which the second Mylar ply is applied to the mandrel. By virtue of the iron conforming so closely to the `surface of the mandrel, the Mylar ribbon has only a negligible distance of travel through an unheated air gap between the iron and the mandrel.

Comparable mechanism is employed in conjunction with all Mylar plies in order to soften the coatings thereon and to prepare them for adherence.

From the iron 1149, the rst Mylar strip is delivered angularly to the mandrel so as to be wound spirally thereon with the edges of adjacent turns abutting each other. Immediately after the deposit of the iirstMylar strip, the second strip is applied to the mandrel from similar feeding and heating mechanism 129 with, however, the adhesive side downward or inward so as to meet and bond to the outwardly facing adhesive on the rst strip. The `second strip is deposited on the mandrel so as to span and cover the abutting edges of the rst deposited strip.

Silicone treated driving belts 122 are employed for pressure and to urge the plastic `film and paper plies along the mandrel. These belts should be directed angularly of the mandrel in the line of wind of the tubing and to move the tubing longitudinally such angularity may be adjusted by disposing the pulleys 124 or by increasing the diameter thereof so that the belts are in the desired angular relationship.

Paper or cardboard plies may be delivered to the mandrel in any quantity or weight desired as by paper 7 supply rolls 13G` and 131. In the course of the delivery to the mandrel, the paper is directed through an adhesive depositing apparatus 148 and possibly over a guide roller 150 to insure proper placement of the paper ply on the mandrel and on the previously formed Mylar tube liner.

In order to facilitate movement of the tubing along the mandrel and avoid any adherence of the applied layers thereto, it may be desired to introduce a loose strip of paper in a fashion well known in the industry from a supply roller 152. The loose strip is laid directly on the mandrel and the Mylar plies in turn on top of the loose strip. Such procedure is well known and widely practiced in the art and, upon completion of the tubing, the loose strip is simply pulled out of the tubing and discarded.

FIG. illustrates a mandrel for a tube winding machine which has its own integral provision 4for heating the liner plies as they are delivered to the mandrel and subsequently cooling the liner to insure a setting of the fused liner coatings. The mandrel 154 as illustrated in FIG. l0 consists of an outer tubular sleeve 156 which provides the surface on which the tubing is wound. Commonly, this would be of polished steel in order to promote the free movement of the tubing formed thereon along it, but I contemplate likewise a Teflon or some similar fluorinated hydrocarbon coating on the sleeve which will facilitate slip and non-adherence of the tubing even more effectively. At the mounted end 158 of the mandrel or sleeve 156, I enclose an adjustable thermostat 160` in direct contact with the inner surface of the sleeve to be responsive to ternperature changes thereof. The thermostat is connected in series with a heating element 162 by a lead 164 which includes a heating coil 166 spaced inwardly from the mounted end of the mandrel and lying close to the inside surface of the sleeve 156. The other leads 168 of the thermostat and coil extend outward through the mounted end of the mandrel. I likewise provide an insulating plug 17() at the mounted end of the mandrel through which the leads 168 extend and which serves to maintain the location of the leads, thermostat and heating coil.

The remote end 172 of the heating coil is contained against a water-proof insulating plug 174 which fills the interior of the mandrel sleeve 156. Likewise, a coil form 176 of insulating material extends axially through the heating coil 166 between plugs 170 and 174.

The remote free end 178 of the mandrel is closed by a metal plate 18) welded to the end of the sleeve. Likewise, a plate 182 bisects longitudinally the interior of the free end of the mandrel to divide the remote end of the mandrel into two chambers 184 and 186. The plate 182 does not extend quite to the closure plate 180 and thus leaves a communicating pasage 138 between the two chambers 184, 186.

A pair of tubes 190 extend through the plugs 170, the coil form 176 and the water-proof plug 174 and open respectively into the chambers 184 and 136.

The way in which my mandrel operates is evident. The area of the mandrel heated by the heating coil 166 is of sutiicient length to receive both of the Mylar plies and to effect a heating thereof sufficient to cause the polyethylene coating to fuse and thus weld the two strips together. As the plastic tubing then migrates along the mandrel, it comes to that portion thereof outside the chambers 184, 186. The tubes 190 are connected, one of the ltubes to deliver a coolant into the chambers 184, 186 and the other tube to exhaust the coolant therefrom. That portion of the mandrel being thus cooled, positive assurance is given that the coating material sets to bind the plies together.

As a further aspect of my invention, I may also provide rollers 192 arranged to bear on the overlapped plies of Mylar film in the zone of heating to ensure positive and continuous bonding as between the plies and to avoid bubbles or ply separation. These rollers are desirably mounted at right angles to the helical movement of the plies on the mandrel. This, of course, means that the axis of the rollers will be inclined relative to the axis of the mandrel. I, therefore, make the rollers concave in order that they may bear on the surface of the mandrel over their entire length. These rollers, of course, should be situated so `as to press the plies together at a point in their travel on the mandrel where the coating material is still plastic and adhesive. The illustrated roller 192, used in conjunction with the heated mandrel should be spaced from the point of application of the Mylar plies to the mandrel a sufficient distance so that the polyethylene coating has an opportunity to soften and become tacky. On the other hand, `in the case where the Mylar plies are heated before application to the mandrel, the rollers should 4be situated as close as possible to the point of application of the outer Mylar ply.

To make the tubing of which my can bodies are formed, I may apply first the loose paper strip directly to the mandrel from the supply roll 152. This paper is laid on the mandrel with edges abutting. The paper strip is employed simply to avoid the sticking of any tubing material to the mandrel and to minimize frictional binding of the tubing on the mandrel. This expedient of providing an initial wrap on the mandrel of a loose strip is a well recognized technique in the production of tubing. In some instances, tubing manufacturers apply an oil spray to the loose strip to insure more positively non-adherence of the tubing proper to the loose strip.

The first Mylar ply is thereafter applied to the mandrel with its coated side outward on top of the loose strip, if used. Either the heated mandrel or the pre-heating mechanism illustrated in FIG. 9 may be employed to obtain the desired softening of the coating or the two heating techniques may be employed in combination. Thereafter, the second inner Mylar ply is applied to the mandrel with edges of consecutive turns abutting and the strip centering on the `abutting edges of the first of the plies. The coated side of the second Mylar ply is, of course, inward in contact with the coating of the first applied ply. The second applied ply may be pre-heated just as the first ply. By virtue of the hot tacky coatings and the strains implicit in winding the plies on the mandrel, the two coatings bond securely together, and the roller 192 may be employed to further and make more uniform this bonding.

After the two Mylar plies have been applied to the mandrel, the paper backing may be applied on top of the Mylar liner. Two strips of paper will be delivered from supply rolls 13C and 131 through glue baths 148 and over guide rollers onto the mandrel. Although two paper strips have been illustrated, these may be multiplied as desired or even reduced to one. The paper strips may be laid with edges abutting or overlapped should such structure be desired. The adhesive binds the paper strips together and to the underlying Mylar liner. The tubing may be completed by final application of an ornamental glazed paper, but as this is so completely conventional, illustration has not been deemed necessary.

Tubing of this character may be employed as a container body for a vast variety of liquids, but there are certain `applications where a container should have an impervious outer coating as well as an inner coating. Such an instance may arise where a container will be exposed to circumstances of high humidity or immersion in water. A very specific instance which occurs to me is a container for beer, it being a common practice to throw beer containers into a tub of cold water to chill them quickly.

To make containers of this characters, I contemplate that the tubing as formed in the first described process and consisting of the inner Mylar liner and the paper tube around it be simply wrapped again with a double Mylar outer liner in precisely the same fashion as the inner liner was formed. Thus, the apparatus from which the inner liner is formed, the supply rolls 128 and 129 and ancillary equipment, will be duplicated after the final application of the paper ply as at 132 and 133 to deliver a final two plies of Mylar on the top of the paper.

In this instance, it will be evident that the pre-heating techinique or mechanism as illustrated in FIG. 9 must be employed in order to obtain the bonding of the Mylar plies together since it would be difficult to transmit heat through the already formed inner parts of the tube and there might also be unfavorable effects on the inner liner such `as a separation of the plies thereof. In such case, a first Mylar ply will be pre-heated and applied to the adhesive-coated outside of the paper layer of the tubing, coated side out with edges abutting and on top of this the second ply, coated side in and centered on the edges of the inner ply. The plies may be pressed together and against the paper by a roller 194 similar to roller 192.

Although I have described my invention in the very specific terms of using a Mylar ply with a polyethylene coating, there are many `other materials which can be employed. There are other impervious lms having `a relatively high melting point and coatings which can be apl plied to these films which may be softened to bond two sheets together.

Indeed, polyethylene itself may be used. In such case, I contemplate that the loose strip will necessarily be used and a polyethylene strip be applied to it. On top of the polyethylene strip, I may lay a paper strip having a polyethylene coating on it, coated side down and overlapping the edges of the rst applied pure polyethylene strip. The heating in this case is obviously desirably done after application of the polyethylene strip to the mandrel and after paper strips have been applied. I find in such case that the loose strip serves not only to prevent adherence of the polyethylene strip to the mandrel but likewise imparts suicient tensile strength during the course of winding so that the softened polyethylene strip need absorb none of the tensile load in winding. Polyethylene does not adhere to paper, not having been subjected to certain special treatments, and, therefore, the loose strip may be easily torn out of the completed tubing.

It will thus be appreciated that the pure polyethylene strip plays the part of the inner Mylar strip 128 and the polyethylene coated paper serves the same function as the second Mylar strip '129 of the illustrated example.

I have described the tubing of my invention rather specifically as the plastic strips being laid on the mandrel with edges abutting. This again need not necessarily be the case. The edges of the strips may be lapped and, indeed, they may even be lapped to double the thickness of the plastic liner. 4In the case of the polyethylene liner, the polyethylene strip may be of such width or so inclined to the mandrel as to provide a 'double thickness of the polyethylene sheet in addition to the polyethylene coating on the paper to be applied thereabout.

I have likewise described two specific mechanisms whereby the plastic sheets may be heated so as to obtain a bonding, but it will be evident that other techniques may be employed to achieve this heating. For instance, the lm may be heated by passing it through a heated chamber or by exposing the film to infra-red radiation, either before or after winding it on the mandrel. Like- Wise, cooling may be achieved either by simple radiation or by blowers. The application of the glue-coated paper strips might easily provide adequate chilling of the plastic strips in order to set the adhesive coatings.

It will be appreciated that while I have described my can and its advantages in terms of liquid contents, it is equally sutiable for packaging solid or semi-solid contents. My container is Well suited to the packaging of foods and performs in superior fashion in the storage of dry but deliquescent and corrosive chemicals, such as lye and the like.

It will, therefore, be lapparent from the foregoing description that my invention is capable of being practiced in many different ways and in taking many different forms and I, therefore, desire that it be regarded as being limited only as set forth in the following claims.

I claim:

l. A liquid container comprising a tubular paper body portion having a spirally wound, liner of liquid-impermeable plastic, said plastic liner having adjacent windings overlapping and heat sealed at their margins to provide a continuous liquid-impermeable lining and end members secured to the ends thereof in liquid-tight relation against liner said end members including an annular U-shaped rim engaged over the ends of said body, the inside walls of said rims having an annular indentation therein bearing against the inside of the ends of said body portion in liquid-tight relation.

2. A liquid container comprising a spirally Wound paper body portion having interior and exterior, spirally wound, plastic coverings of liquid-impermeable plastic, said plastic coverings having adjacent windings overlapping and heat sealed at their margins to provide continuous interior and exterior' liquid-impermeable coatings and end members secured to the ends thereof in liquid-tight relation against said coverings said end members including U-shaped annular rims engaged over the ends of said body, the inside and outside of said rims having opposite annular indentations therein seizing and compressing the ends of said body therebetween.

3. A container comprising a tubular body portion and end members for the ends thereof, said body portion cornprising a tubular paper body having a spirally wound lining of liquid-impermeable plastic, said plastic liner having adjacent windings overlapping and heat sealed at their margins to provide a continuous liquid-impermeable lining, one of said members including an outwardly extending, inwardly directed, U-shaped metal rim receiving one end of said body and a center portion spaced inwardly of said end of said body, the inside of said rim having an annular indentation therein bearing against the inside surface of said end in liquid-tight relation.

4. A paper can comprising a tubular body portion and end members for the ends thereof, said body portion comprising a tubular paper body having a spirally wound lining of liquid-impermeable plastic, said plastic liner having adjacent windings overlapping and heat sealed at their margins to provide a continuous liquid-impermeable lining, said members including a metal shell having a central portion and an annular, outwardly extending, inwardly directed, U-shaped rim, a plastic shell having a surface conforming to the inside surface of said metal shell to have a U-shaped rim receiving the ends of said body member, said metal shell having a circumferential indentation on the exterior of the inside surface thereof compressing the adjacent surface of said plastic shell against the inside surface of the ends of said body.

5. A container comprising a tubular body portion and end -members for the ends thereof, said body portion cornprising a tubular paper body having a spirally wound lining of liquid-impermeable plastic, said plastic liner having adjacent windings overlapping and heat sealed at their margins to provide a continuous liquid-impermeable lining, one of said members including a plastic shell having a central portion and cylindrical rim extending in one direction from the periphery of said central portion, said rim being received in one end of said body portion even with the edge thereof, said center portion being inward of said end, and an annular, U-shaped metal rim containing said plastic rim and said end, said metal rim having externally formed annular :grooves in the inside and outside surfaces thereof compressing said plastic rim and said end togethen 6. An end member for one end of a tubular container comprising a metal shell having an aperture therein, the edges of said aperture being upwardly and outwardly recurved, a plastic shell conforming on its upper surface to the underside of said metal shell and having a tubular extension extending through said aperture of said metal shell, said extension being upwardly and outwardly curved on its outer surface to conform to said curvature of said aperture edges and secure said shells together, and means on the rims of said shells for securing said shell together to said end of said container.

7. An end member for one end of a tubular container comprising a metal shell having a pouring spout formed therein and having an aperture in said metal spaced radially from and in the vicinity of said pouring spout, a plastic shell conforming to the underside of said metal shell and extending up through said pouring spout to form a liner therefor, said plastic shell including a portion thereof extending upwardly through said aperture in said metal shell and having a head thereon to secure said shells together, and means at the edges of said shells for securing said shells together to said end of said container.

8. An end member for one end of a tubular container comprising a plastic shell having a cylindrical upstanding externally threaded pouring spout therein and an upstanding cylindrical rim proportioned to lit closely in said end of said container, a metal sleeve having threads embossed therein threaded on the exterior of said pouring spout, said sleeve having an external circumferential indentation therein below the area of threading engaging circumferentially said pouring spout, and an annular, channel-shaped rim proportioned to contain closely said rim of said plastic shell and said end of said container.

9. A liquid container including a spirally wound body portion comprising, from inside out, two liquid-impermeable plastic plies having a coating between said plies, the plastic plies being fused together by said coating, and a plurality of relatively strong, liquid-permeable, fibrous, glued plies about said second plastic ply, and ends for the top and bottom of said body said ends including an annular U-shaped rim engaged over the ends of said body, the inside walls of said rims having an annular indentation therein bearing against the inside of the ends of said body in liquid-tight relation.

l0. The combination as set forth in claim 9 wherein said plastic plies consist of liquid-impermeable lilm stable to a relatively high temperature and said coating has a temperature of fusion substantially lower.

11. The combination as set forth in claim 9 wherein said plastic plies comprise a film having the general characteristics of Mylar and said Coating is of a liquid-impermeable plastic having the general characteristics of a polyethylene with a temperature of fusion in the general vicinity of 100 to 125 C.

12. The combination as set forth in claim 9 including additionally a third and fourth ply of, liquid-impermeable plastic on the exterior of said fibrous plies, said third and fourth plies having a coating therebetween by which said plies are fused together.

13. A liquid container comprising a fibrous tubular container body having an inner, spirally Wound liner of liquid-impermeable plastic, said plastic liner having adjacent windings overlapping and heat sealed at their margins to provide a continuous liquidimpermeable lining, and a top and bottom for said body, said top and bottom comprising an outer metal shell having an annular channel-shaped rim and an inner-liquid-impermeable plastic shell conforming to and lying against the inside surface of said metal shell, the annular channel in said plastic 12 shell defined by said conformity to said metal shell receiving closely an end of said body, one side of said channelshaped rim of said metal shell having a circumferential indentation therein indenting circumferentially the portion of said plastic shell inward thereof and the end of said body received in said channel.

14. The combination as set forth in claim 13 wherein said opposite circumferential indentations effect a compression of the end of said body received in said channel therebetween.

15. A liquid container comprising a brous tubular container body having an inner spirally wound liner of liquid-impermeable plastic, said plastic liner having adjacent windings overlapping and heat sealed at their margins to provide a continuous liquid-impermeable lining, and `a top and bottom for said body, said top and bottom comprising an outer metal shell having an annular channel-shaped rim and an inner, liquid-impermeable plastic shell conforming to and lying against the inside surface of said metal shell, the annular channel in said plastic shell defined by said conformity to said metal shell receiving closely an end of said body, said channel-shaped rim of said metal shell having opposite circumferential indentations in the sides thereof indenting circumferentially the portions of said plastic shell inward thereof against the end of said body received in said channel.

16. A liquid container comprising a fibrous tubular container body having an inner, spirally wound liner of liquid-impermeable plastic, said plastic liner having adja cent windings overlapping and heat sealed at their margins to provide a continuous liquid-impermeable lining, a bottom secured to one end of said body and a top secured to the other end of said body, said top comprising a rnetal shell having an aperture therein and a rolled bead surrounding said aperture, a plastic shell lying against the inside surface of said metal `shell and conforming thereto, said plastic shell including a tubular extension extending through said aperture, said tubular extension having an annular groove about the exterior thereof receiving the inside surface of said bead.

References Cited in the le of this patent UNITED STATES PATENTS 1,698,260 Smith Ian. 8, 1929 1,944,970 Dieffenbach Jan. 30, 1934 2,188,497 Calva Jan. 30, 1940 2,230,987 Karl Feb. 4, 1941 2,331,969 Friedrichs et al Oct. 19, 1943 2,349,730 Horning May 23, 1944 2,434,756 Brooks Jan. 20, 1948 2,456,483 Beattie Dec. 14, 1948 2,511,481 Schneider June 13, 1950 2,623,680 Wilcox Dec. 30, 1952 2,631,509 Whytlaw Mar, 17, 1953 2,801,041 Kruszynski July 30, 1957 2,819,001 Pottle Jan. 7, 1958 FOREIGN PATENTS 553,590 Canada Feb. 25, 1958 

